A toy for concentration / relaxation.

It is a very tight fit. The model has been adapted to my printer. You may need to make changes to get the pieces together. Print 2 pieces and see if they fit together. It should be so tight that it hurts in the fingers when you put the pieces together, but there should still be room so that the pieces can spin relatively easily in each other once they are put together. When assembling push together and twist the pieces. Might need e rasor to trim all sth support material away from the socket. In my model i used 18 pieces!
I printed them in the same position as they are presented in the .stl file. A lsmall brim and support everywhere. Infill 60% line

Good luck!